The Laboratory of Flow Cytometry was created in 1988 the several flow cytometry units at Roswell Park Cancer Institute into a single Resource. Today, the Laboratory is organized to provide researchers with advanced state-of-the-art flow cytometers and an extensive computer network have been assembled into a user friendly environment by staff partially supported by this grant. As a focal point of many interdisciplinary activities throughout RPCI, the Laboratory of Flow Cytometry is a multi-purpose laboratory that provides both basic and clinical protocol services to the RPCI staff. It also maintains its own research programs. The goals of the laboratory are to provide: Multiparameter flow cytometry service to basic and clinical research investigators, teaching and technical support as required for these investigators, and maintain an electronic communications network and long term storage for flow cytometric data. To accomplish these goals, the Resource is divided into a clinical and a basic research component. These goals are met by trained staff who either perform the studies or who train users to perform their own studies. The educational program provides didactic lectures and hands-on experience with isolation, preparation, handling and usage of all types of human and animal tissue. Strategies for staining cells with multiple fluorescent probes simultaneously for general or unique applications are presented, discussed and performed. These include combining immunophenotyping cells using antibodies to extracellular antigens with molecular phenotyping using oligomer probes. Instrumentation setup for three-laser excitation, data acquisition and high speed cell sorting at rates up to 20K/sec are provided. The analysis of multi-parameter data using several software programs is also provided. The Flow Cytometry Laboratory is located on the sixth floor of the Science Building and occupies 4500 square feet. The Resource as a complete Molecular Biology Laboratory, Tissue Culture, Laboratory, Optics and Electronics Laboratory, Fabrication Shop, General Biology Laboratory, and Computer Laboratory.